The construction of structures based on calcium hydroxide has gained popularity since builders became aware that the said material has exceptional properties in terms of noise insulation and heat insulation, and also concerning hydraulic exchanges. Mixtures of calcium hydroxide with particles or fibers have been developed, in particular but not exclusively wood shavings and hemp, to produce screeds, partitions, insulating claddings for doubling existing walls, or partition fillers for wood-framed houses. The results are indisputable, so that the material certainly has an assured future when one considers the trend toward ecological designs that seek simple and natural methods for producing products that can be recycled and that favor energy economy.
Until now a material referred to as hydraulic lime has been commonly used, which contains essentially between 10 and 20% of clay and which is calcium carbonate that has been heated in a furnace to temperatures of the order of 1200° C. and in any case lower than 1500° C. However, some of the natural lime, transformed to slaked lime referred to as hydrated lime, has nevertheless already been transformed to cement, referred to as Portland cement, during the process. The result is that the material obtained, which sets relatively rapidly, becomes particularly inert and to some extent loses the properties sought, namely:    its ability to become a hydraulic absorbent, which takes up moisture and then releases it and so plays the part of a thermal regulator; and    its ability to absorb relatively large amounts of carbon dioxide, so giving rise to natural carbonation and hardening that increases with time.
Furthermore, it should be noted that hydraulic lime is a manufactured product which is at present only found in industrialized countries and which is most certainly more expensive than the almost natural hydrated lime found cheaply all over the world. The problem associated with hydrated lime is that of its setting and hardening. In fact it sets very slowly, which is a drawback for the use of the material despite its advantages in other respects. For that reason it is almost impossible to use in practice.
German Patent No. 16753 of 1881 describes a process for producing a mass intended for the construction of parts of a building, in particular a flame-proof cladding and a floor. The mixture of materials described by the said patent, and in particular its two Claims 1 and 2, comprises among other things especially slaked lime and cement to which have been added relatively disparate mineral compounds such as gypsum, chalk, and sand, and organic substances such as blood. The presence of cement has the advantage that is accelerates the hardening of the mass, but its major disadvantage is that it prevents the natural carbonization of the lime which advantageously takes place by natural and progressive absorption of carbon dioxide. Because of that, the process described does not in any way respond to the problem solved by the present invention.